This invention relates to a control system for a disc player apparatus in which a disc is placed on a turntable of the player by means of a disc lifter, and particularly to improvement of a clutch control system for selectively coupling drive power to the disc lifter.
In a certain disc player, e.g., in a video disc player, a disc to be played back is placed on a turntable of the player by means of a disc lifter. Thus, the disc is first put on the lifter in a disc set mode (disc receiving standby state). Then, in a playback mode, the lifter descends so that the disc is lowered onto the turntable, and the playback operation is commenced. Where the disc is to be taken off, the lifter ascends so that the disc is lifted from the turntable. Generally, the above-mentioned ascending/descending operation of the disc is performed by a mechanism comprising a reversible motor, a lifter (disc cradle), a transmission gear assembly for transmitting drive power of the motor to the lifter, and a clutch for selectively effecting the power transmission of the gear assembly. Whether or not the clutch enables the gear assembly to transmit the drive power is determined by a clutch solenoid. Thus, when the solenoid is electrically energized, the gear assembly transmits the drive power from the motor to the lifter. When a system power switch of the player apparatus is OFF, the solenoid is not energized, and the clutch is disabled so that the lifter automatically descends. In such mechanism, since the solenoid is always energized while the system power is ON, unavailing power consumption for the solenoid is inevitably invited. Further, if one forgets to turn the power of the ray or to the OFF position in the disc set mode, the disc is maintained in its raised state for a long period of time, and therefore the possibility exists that the disc may become warped resulting in a noticeable vibration of the disc plane, especially at the outer periphery of the disc plane, upon rotation of the disc. Such vibration due to the warped disk is quite unfavorable for a stable and reliable playback operation of the player.